Sun screen



W 1943 J. J. G REB.E a -rAL v 2,319,225

SUN SCREEN Filed Jan. 1:5; 1941 2 Sheets-Sheet 1 NVENTOR Jail/V M 6251:Mlklfyl. EW/l/d ATTOZNE' May 18, 1943 J. J. GREBE Em 2,319,225

sun SCREEN Filed Jan. 13, 1941 2 Sheets-Sheet 2 j V V INVENTOR JOHN J 6255! I BY l l Alkliy 5 iW/A i 71/54 Arron E-Y simple operations frmaterial.

- panying drawings, in which Patented May 18, 1943 UNITED STATES PATENTOFFICE,

SUN SCREEN John A J; Grebe, Midland,

Grand Rapids, Mich., assignors to Ewing Deand Walliley Ewing,

velopment Company, Bay City, Mich., a corpo-' ration of Michigan aApplication January 13, 1941, Serial No.,374,194

' 1 Claims.

direct rays of the sun both when the s-u'nis at a high altitude and'anazimuthal angle ro ghly normal to the shade and when the s' n is nearlyon the horizon and at an oblique a gfle to. the

screen, and which at\ the same time wil permit materially greater visiondirectly through the screen than domost conventional shades.

Another object is to provide a screen whichils can bereadily andinexpensively fabricated by,

' om a single piece ,of sheet These and other objects are accomplishedin the-'sun-screen of the invention, which consists essentially of aplurality of parallel strips of sheet material spaced at intervals notgreatly exceeding'the width of a strip, and spaced paral; lel legs ofsheet material inclined to the general plane of the screen andconnecting the stripswat intervals along the lengths thereof, ashereinafter described tvith reference to the accom- Figure 1 is anenlarged front elevation of a small portion of a preferred form of thesunscreen according to the invention;

Figure, 2 is a cross-section alang the line 2-2 of Figure 1; 1

Figure 3 is an en of slltted blank us Figuresl and 2;" p

Figure 4 is an enlarged perspective view showing theiblank of Figuredpartially expanded into the screen of Figures 1 and 2; and v Figure 5 isan enlarged perspective view of an-./

larged plan view of a portion I e'd inmaking the screen of 5 other,formoi screen according to the "invention.

The sun-screen illustrated ingFigures 1 and 2 is formed by slitting andfolding a single sheet of material, as will be explained, and consistsof a series of parallel strips 6 of elongated crosssection which arevertically superposed at equal intervals not greatly exceeding, andpreferably 5 approximately equal to, the width of a strip, and areinclined, preferably at least 45, tothe general plane of thescreen, i.e. to the vertical. As shown, each individual strip 6 extendshorizontally across thescreen and lies in a singlefplane, and is offsetregularly in the same direction at equal intervals along its length, asat 1, the distance of offse't'not exceeding about three-fourths thewidth of the strip, and being advantageously about one-half.such width.The strips 6 are joined together by vertical rows of legs 8 formed ofsheet material integral with that oflthe strips,

each leg having a width substantially equal to I the regular olfsetdistanceof each strip, *1. e. not

greater than about three-fourths the width of a strip, and connecting afront portion 9 Of a strip with the corresponding oppositely offset rearedge ID of an adjacent strip. The rows of legs 8 are ordinarily spacedapart a distancelarge in comparisonto the intervals between adjacentstrips.

As will be seen from the drawings, the'legs' 8 areinclined to thegeneral plane of the screen, and are also rather sharply inclined to thestrips to which they are attached. The legs in any given row areordinarily in the saine or in parallel vertical planes, and preferablyhave their centers all in thes'ame vertical line, in order to give agenerally rectangular appearance to the screen. 1 i m While thesun-screen is illustrated with only .two offsets per strip and tworowsof legs, it will be appreciated that it may comprise any number ofoffsets and corresponding rows of legs, t'o'form a screen of thedesireddimensions. In general, the width of a strip will be from one-eighth toone-half inch, and the distance between rows of legs 7 one-half to fiveinches," although other sizes are eq all possible. The scr'een isusually fabricated }f thin sheet metal, but may also be formed of 0 herflexible, strong materials, such as synthetic plastic sheet.- I F Inmaking the sun-screen ill strated, thesheet material is first slit toform a i ank, as in Figure 3, which is then formed into e screen. In theslit blank, which is prefera 1y rhomboidal in shape to avoid waste, thesli s are all substantially parallel to one'another', and are disposedon he bias to anedge of the' heet, thebias angle ill being determined asereinafter explained. As shown, the slits are arranged in a plurality oflikeparallel series, as at 12 iand l2. The individual lines within aseries are regularly offset a distance which does not exceedaboutthree-fourths the distance between correspond ing' lines'ofadjacentserieaand overlapat their offset positions a distance which doesnot great-,

' ly exceed, and need not equal, the distancebetween corresponding linesof adjacent series. As a result of "this slitting, there are formedparallel continuous regularly olfset strip mem-. bers 6 interconnectedat their corresponding oppositely offset portions by leg members 8.

The blank slitted as described is formed into sun-screen by successivelydisplacing each strip member 6 by accurately controlled means, in adirection diagonally downward and backward substantially in the biasdirection, 1. e. parallel to the long edge of the strip, thus forcingthe strips into vertically superposed parallel planes, and causing theleg members 8 to become sharply inclined to the strips and to thegeneral plane of the screen. A partially folded blank showing two of thestrip members already displaced into position is illustrated in Figure4. The displacement of the strip members 6, and the concurrent formationof the legs 8, may be rendered more accurate by defining on the blankfold lines l3 to mark the point of juncture of the leg members 8 withthe strips 6, either'by suitably crimping the blank or by other means.The fold lines II are ordinarily oblique to the long edges of the strips8 (as at angle II in Fig. 3) and are preferably in the same or parallelplanes.

The angle at which the strips 8 are inclined to the general plane of thescreen is controlled primarily by the angle H of the fold lines, and toa lesser extent by the bias angle l i. In making the screen, theseangles and the various dimensions oi! the strips 8 and leg members 8 arechosen so that, in the final screen, the strips 6 have an inclinationcapable or providing the desired protection from direct sunlight. Theprecisechoice of these angles and dimensions is made from mathematicalformulas which have been developed from the geometry of the screen andthe blank.

In use, the sun-screen is ordinarily mounted in a frame or hung in suchmanner that the strip are inclined downand outwardly toward thedirection of the sun, and that the strips 6 are horizontal. For easternand western exposures, where the rays 0! the sun are for the most partat an acute angle to the plane of the screen, the screen is also mountedso that the legs 8 face toward the sun. Thus, if the screen in Figure 1is considered as viewed from outside a window being shaded, it is inposition for use in a westerly exposure, the sun being to the right, orsouth. For an east window, the screen would be inverted, i. e. top forbottom and inside for out, so that the legs face to the left. Likewise,

for certain exposures where it is necessary, seasonal or even diurnalchanges in the general direction of incidence of the sun's rays on thescreen may be met by inverting the screen, thus aflording protection atall times.

The unusual and advantageous characteristics imparted to the sun-screenof the invention by its regularly oiIset strips 8 and interconnectingleg members 8 may best be understood from the following considerations:

The number or hours during the day in which a shading device 0! theVenetian blind type atfordsv complete shade against the direct rays 0!the sun is relatively small. Now. from the geometry or such a device, itwill be evident that, for such devices at most windows, the period ofcomplete shade may be prolonged materially either (a) by rotating thewhole shade, in the lane of the window, to bring the sun more nearlyinto a plane normal to the face 01' the shade and parallel to thevertical center line thereof, e. g. by slanting all the stripsdownwardly from one end to the other, or (b) by rotating the whole shadeabout its vertical center line in that direction which will decrease theangle of incidence of the sun's rays on the shade, e. g. by pushing oneside of the shade out of the window.

Purely for prolonging the period of complete shade, and without regardto practicability, either or both of these rotation are preferable tothe conventional practice of adjusting the strips of the shade to asharper tilt, since, unlike the latter, they do not reduce the open areaof the shade, and hence do not restrict outward vision or excludeingress of reflected light, Of course, with existing shading devices,the rotations described would be so obviously awkward and difficult asto be impractical.

In the sun-screen of the present invention, however, the structure isdivided into many small units in which advantage is taken of both theshade-prolonging rotations discussed, and yet the structure as a wholeremains in the plane of the shaded opening and rectangular to it ingeneral pattern and appearance. Thus, as will be evident from Figure l,in any strip 5, each individual element lying between any two legs 8 isrotated slightly in the general plane of the screen. being inclineddownwardly from left to right. However, because of the regular ofisetmembers I, which exactly make up for this downward slant, the entirestrip 6, constituting a series of individual strip elements which extendfrom one end of the screento th other, presents a strictly horizontalappearance. Again, each individual element extends from left to rightoutwardly from the plane of the screen, but'the offset members in thestrip make up for this extension, so that the screen as a whole issubstantially in a single plane.

While the use of regularly oil'set strips as described tends toward alonger period of complete shade because 01' the two rotations of theindividual shading elements, it will also be evident that if strips weremerely thus offset without further structural provision, materialleakage of sunlight would occur through the screen at the gaps left ateach oflset position. In the screen or the invention, however, the legmembers 8 extend fully from the offset at the edge or one strip to thecorresponding opposite oflset on the adjacent strip, and thus preciselyfill the gap in the shade which would otherwise be present. In otherwords, the presence or leg members 8 at each offset or each strip notonly contributes to the structural unity or the screen, but also isfunctional to the shading purpose or the screen.

Another screen structure according to the invention which retains theadvantageous characteristics Just discussed is shown in Figure 5. Thislatter screen consists of a series or parallel strips 8 which aresubstantially identical with the strips as in Figures 1 and 2. However,in the screen of Figure 5, the legs I interconnecting the strips 6 attheir oiiset positions are formed of sheet material which is verticallycontinuous, and are provided at equal interval with slots I8 into whichthe strips 8 fit. In a slight variation or this structure, the stripsneed not be horizontally continuous, but may be made up or individualelements secured to the legs and offset regularly. to give a structuresubstantially identical with that 01 Figure 5.

The sun-screen or the invention, particularly in the preferredembodiment 01. Figures 1 and 2, possesses a number of advantages otherthan the efllciency or exclusion of oblique rays of the sun alreadymentioned. The screen may be fabricated by extremely simple means from asingle sheet oi. material, and can be made in any desired size. Themetal in the screen is not under stress,

having been merely folded into position. The

structure presents only smooth, flat surfaces, and

If desired, it -may be rolled "up for are possible without departingfrom the inven- ':tion Thus, the screen may be formed of sheet materialwhich is a 'dark color on the top but refiective on the bottom,so'that'the direct rays 'of the sun are absorbed and do not penetratethe screen, butcooler reflected light i'rorntlie near ground'is'refiected inwardly. If desired, the screen maybe fabricated of 'asheet composed of two materials'of differentcoeiilcients' ofexpanfinished screenwill automatically vary .with temperaturechanges,thus permitting the'rays of the sun to pass through the screen to -agreater degree when it is cool than when it is hot. Corrugated stripsmay be provided by using corrugated sheetin making the screen orimpressing corrugations in the forming operation, thereby giving addedstrength to the final screen. Again, the screen may be reinforcedvertically, as by rolling or soldering vertical wires into the screen atthe offset corners of the strips, or may be edged with a continuous tapeor selvage edge secured to or integral with the material forming theindividual strips. Such an edge, which is easily made in the plane ofthe screen during the forming operation, can readily be anchored toframes of any type. and can be rolled or crimped to form seams whichpermit ready joining of two or more screens to produce a widerstructure. These and other variations within the scope of the claimswill doubtless occur to those skilled in the art.

It is to be understood that the foregoing description is illustrativerather than strictly limitative, and that the invention is coextensivein scope with the following claims.

We claim: I I

1. In a sun-screen, a plurality of parallel strips of sheet materialinclined to the general plane of the screen and spaced at intervals notgreatly exceeding the width of a strip, and spaced parallel legs ofsheet material inclined to the gen-. eral plane of the screen andconnecting the strips at intervals along the lengths thereof.

2. In a sunscreen, a plurality of parallel strips of sheet materialinclined to the general plane of the screen and spaced apart atintervals approximately equal to the width of a strip, and spacedparallel legs of sheet material inclined to the general plane of thescreen and connecting the strips at intervals along the lengths thereof.

3. A screen according to claim 2 wherein the strips are inclined to theplane of the screen at an angle of at least 45.

4. A screen according to claim 2 wherein the legs are arranged invertical rows, all the legs in each row being in substantally the samevertical plane.

5. In a sun-screen, a plurality of parallel strips of sheet materialinclined to the general plane of the screen and spaced at equalintervals not greatly exceeding the width of a strip, and spacedparallel legs of sheet material integral with that of the stripsinclined to the plane of the sunscreen and to the strips, and connectingthe front portion of each strip with the rear portion of an adjacentstrip at intervals along the length thereof, the width of a leg notexceeding about threefourths the width of a strip.

"6. Ina sun s'creen, a series of parallel vertically superposedhorizontally extending series of stripyelements', the individualelements of each horizontal series being inclined to the general planeof the screen and t'othe horizontal and being interconnected inoifsetrelation, and leg members connecting the strip elements of each vhorizontal series with the corresponding elements of an adjacenthorizontal series.

7. In a sunscreen, a plurality of parallel vertically superposedhorizontally extending series of "strip elements, the individualelements of each -'sion,'such as a bimetallic laminat'ed'sheefl inthiscase the angle of inclination'of the strips in the horizontal seriesbeing inclined to the general plane of the screen and to the horizontaland being interconnected by offset members, the elements and onsetmembers of each horizontal series together constituting a singleintegral strip lying in one plane, and leg membersi connecting thestrip'elements of each horizontal series with the'corresponding elementsof an adjacent horizontal series.

8. A sunscreen according to claim 7 wherein the horizontally extendingseries of strip elements are vertically superposed at equal dis- 'tancesapproximately equal to the width of a strip element, and wherein theindividual strip elements are inclined to the general plane of thescreen at an angle of at least 45.

9. In a sun-screen, a series of parallel horizontally disposed stripmembers which extend across the screen and are offset at intervals alongtheir lengths and are vertically superposed at intervals not greatlyexceeding the width of a strip. and legs of sheet materialinterconnecting the strips at intervals along their lengths.

10. In a sun-screen, a series of parallel inclined strips verticallysuperposed at equal intervals not greatly exceeding the width of astrip, each strip extending horizontally across the screen in a singleplane and being ofiset at regular intervals along its length, and legsof sheet material inclined to the general plane of the screen andinterconnecting the strips at the offsets thereof.

11. In a sun-screen, a series of parallel strips of sheet materialvertically-superposed at equal intervals not greatly exceeding the widthof a strip, each strip being inclined to the general plane of the screenand extending horizontally across the screen in a single plane, andbeing offset at regular intervals along its length a fixed distance notexceeding about three-fourths the widths of a strip, and legs inclinedto the plane of the screen and formed of sheet material iiitegral withthat of the strips and connecting the offset portions of each strip withthe corresponding oppositely offset portions of the adjacent strips.

12. A sun-screen formed by slitting and folding sheet material andcomprising a series of parallel strips vertically superposed at equalintervals not greatly exceeding the width of a strip,

each strip being inclined at least 45 to the general plane of the screenand extending horizontally across the screen in a single plane, andbeing regularly oiIset at equal intervals along its ularly offsetoverlapping slits, said slltted sheet thus defining a plurality'otparallel continuous regularly ofiset strip members interconnected attheir corresponding oppositely offset positions by leg members.

15. Abl'ank capable of being formed into a sunscreen comprising a sheetsubstantially rhomboidal in shape and having therein and at an acuteangle to an edge thereof a plurality of like parallel. series ofparallel regularly otlset overlapping slits in which the regular offsetdis- 20 tance between slits within each series does not exceed aboutthree-fourths the distance between corresponding slits of adjacentseries, and in which the distance of overlapping between slits within aseries does not greatly exceed the distance between corresponding slitsof adjacent series, said slitted sheet thus defining a plurality ofparallel continuous regularly offset strip members interconnected attheir corresponding oppositely oflset portions by leg members.

16. The method of forming the blank defined in claim 14 into a sunscreenwhich comprises successively displacing each strip member diagonallydownward and backward in the bias direction to force the strips intosubstantially parallel v planes and to cause the leg members to becomeinclined to the strips and to the general plane of the resulting screen.

JOHN J. GREBE. WALKLE'Y B. EWING.

